Fuel Supply Control Device for Accurate Flow Measurement
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Solution Overview
Problem
Conventional fuel supply systems suffer from poor reproducibility in measuring discharge flow rates due to hysteresis in pressurizing valves, leading to insufficient accuracy in fuel supply.
Innovation Solution
A fuel supply control device that calculates the internal leak area and pump volume efficiency using the rotational speed, fuel temperature, differential pressure, and flow rate coefficient of the high-pressure pump to improve measurement reproducibility and accuracy of fuel supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pressurizing valve is used to measure discharge flow rate of the gear pump, then fuel supply accuracy can be improved, but measurement reproducibility deteriorates due to hysteresis in the pressurizing valve
Solution Approach 1:
The patent extracts the measurement function from the pressurizing valve by introducing a separate flow rate measurement device (flow meter) that directly measures the discharge flow rate of the gear pump. This separates the measurement function from the pressure control function, eliminating the hysteresis problem inherent in using the pressurizing valve for measurement while maintaining accurate fuel supply control.
2Use of energy by moving object
If the gear pump operates at the same rotational speed, then energy consumption is reduced, but discharge flow rate decreases over time due to internal leak increase
Solution Approach 1:
The patent implements a feedback control system where the flow rate measurement device continuously monitors the actual discharge flow rate of the gear pump. When the measured flow rate deviates from the target value due to pump deterioration, the control device adjusts the pump's rotational speed to compensate. This allows the system to maintain accurate fuel supply while adapting to pump aging, preventing excessive energy consumption that would occur with fixed-speed operation.
Data Source
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AI summary
A fuel supply control device (F, F1) is provided in which a parallel flow path of an orifice (8) and a pressurizing valve (7) is used as a complex pressurizing valve for a fuel supply amount, and which controls a fuel supply pump (3) on the basis of a pressure difference before and after the complex pressurizing valve that has been detected by a pressure difference meter (9). When the rotational speed (N) of the fuel supply pump (3) is below a predetermined threshold value, the fuel supply pump (3) is controlled on the basis of a first fuel measurement amount (Q1), and the fuel supply pump (3) is controlled on the basis of a second fuel measurement amount (Q2).